This is not new. Happened to me many moons ago when the game was young. I made people officers way too soon and got my guild of around 200 wiped out.
Then I made someone GM temporarily and through no fault of his, he lost his phone and couldn't transfer his email to his new phone because he didn't back up his stuff (that bit probably was his fault).
So I lost the gh and the guild.
Don't promote people to officers until you can be absolutely sure they are trustworthy. At least you can start again so that's one consolation. Good luck and best wishes with your guild. 🙂